One of the greatest things about work
One of the nicest things about my workplace is that every so often, the people who have had a birthday in recent months bring cake for all to share, and the division gathers and feasts at afternoon tea time. It's just wonderful 
Not just because I love cake, although that too is true, but because it brings the division together to socialise in a way that we don't often get the opportunity to do.
Let me explain LOD is spread over three buildings, so we rarely see the others unless we already know them and schedule a meeting! I go for weeks only seeing the human factors people and a few motley visitors form other buildings/divisions, and I think that the cake break provides opportunity for networking and promotes group cohesion.
Which in turn makes for a more efficient company, because communication channels are opened, networking is performed and people get to know who to talk to when they need something. In a large organisation, this is appears to be a valuable efficiency strategy.
For those in business, how does your workplace build cohesion?